The invention relates to a safety device for a manufacturing machine such as a folding press.
From WO 01/56720 A1 of the same applicant a safety device for a manufacturing machine, e.g. a folding press, is known. This comprises a beam emitter and a beam receiver. The latter are secured by means of a retaining mechanism to a press beam that is adjustable by means of a drive unit relative to a stationary press beam and form a beam curtain directly in front of bending tools facing an operator which extends over the entire length of the press beam. The safety device is connected to the control device of the press by cable and if there is an interruption in the beam curtain it detects objects in the vicinity of the bending tools in order effectively to prevent the operator being put at risk. The retaining mechanism is detachably secured directly in a mounting device securing the bending tools.
The objective of the invention is to create a safety device, by means of which a tool on the manufacturing machine can be replaced with a simple adjustment of the safety device without taking the latter apart.
The objective of the invention is achieved by providing a safety device in which the adjusting mechanism has a guiding and locking device switching a locking element of a locking device between a released position and a retained position, and the retaining mechanism for the beam emitter and/or the beam receiver automatically locks in relation to the press beam in a park position upon a linear displacement in a direction opposite to the working plane on reaching the park position. The surprising advantage here is that by determining a park position for the retaining mechanism, depending on the overall adjustment range to a working position provided in a different position relative to the press beam, and determined by the different tool heights, an adjustment can be carried out easily and reliably in order to move elements of the safety device out of positions that hinder the refitting of the manufacturing device by means of the locking device that can be shifted in a linear adjustment.
A design is also possible in which the guiding and locking device is arranged on the adjustable press beam in a stationary manner, as in this case the adjustable retaining mechanism can be made to have a light structure.
An embodiment is also possible in which the guiding and locking device is arranged on the retaining mechanism in a stationary manner, whereby the retaining mechanism is given a modular structure.
According to further advantageous developments described herein, a simple technical construction is obtained which ensures a high degree of safety and can be manufactured economically.
In accordance with some embodiments, a variant is possible in which the guiding or locking device is arranged stationarily either on the press beam or on retaining means.
The present application also describes an advantageous design according to which a simple actuation of the locking element of the locking device is achieved, in which the locking element is pretensioned by means of a spring arrangement such as a compression spring acting between the locking element and a guide housing for the locking device, so that the locking element projects beyond a side surface of the guide housing in the direction of a stop and switching means, and wherein the stop and switching means forms an adjusting means that exerts an adjusting force on an end face of the locking element against the action of the spring arrangement.
According to the further advantageous designs in which the adjusting means is in the form of a retaining stop for supporting the locking element or the retaining mechanism, the components are simplified and thereby the assembly much facilitated.
A design in which a guide rail for the guiding and locking device is arranged in a housing sleeve formed by at least one section is also advantageous however, as in this way a closed unit is obtained and unauthorised intervention is prevented.
By arranging the safety device such that, at an end region facing the standing surface on the housing sleeve a support plate aligned parallel to the standing surface is arranged for the beam emitter and/or the beam receiver, the fitting of safety elements onto the safety device is simplified.
Designs are also advantageous in which lines are arranged in the housing sleeve for the transmission of energy and data between the beam emitter and/or the beam receiver and an output interface, in that the safety device can be attached easily to the machine control, whereby the assembly is simplified, and furthermore the safety device according to the invention is particularly suitable for subsequently fitting onto production devices that do not have this device.
By providing the safety device such that an adjustment path of the retaining mechanism starting from the park position can be adapted to various working positions by stop means such as pins insertable into the guide rail, the beam emitter and beam receivers can be set in preset positions that are set at different tool heights.
Finally, an effective, automatic locking can be achieved in a park or working position of the retaining device for the beam emitter and also the beam receiver and an adjustment into a deeper position, in accordance with other embodiments of the invention, by providing the locking device as a wedge element mounted adjustably in the housing of the guiding and locking device. This requires a conscious effort to carry out an unlocking procedure, which reduces the risk of error.
Furthermore, the design is technically of high standard.